Effect of percutaneous coronary intervention on global hemodynamics and the prevalence of residual microvascular dysfunction

OBJECTIVES: We aimed to examine the changes in hyperemic coronary sinus flow (CSF) and global coronary flow reserve (g-CFR) after percutaneous coronary intervention (PCI) and investigate the predictors to improve these metrics and the prevalence of residual coronary microvascular dysfunction (CMD). METHODS: This prospective, single-center study included 118 patients with stable coronary artery disease undergoing PCI for a single proximal lesion. Phase-contrast cine-cardiac magnetic resonance (PC-CMR) was used to assess hyperemic CSF (HCSF) and g-CFR, before and after PCI. Residual CMD was defined as concordantly impaired post-PCI HCSF (<2.3 ml/min/g) and g-CFR (<2.0). RESULTS: HCSF significantly increased, although 38 (32.2%) patients showed a decrease. There was no significant change in g-CFR despite fractional flow reserve (FFR) improvement in all target territories. Concordantly increased HCSF and g-CFR were effectively discriminated by adding PC-CMR-derived information to pre-PCI FFR. Residual CMD was observed in 30 (25.4%) patients and was associated with pre-PCI renal dysfunction and lower pre-PCI rest and hyperemic CSF, but not with pre-PCI regional physiological indices. CONCLUSIONS: FFR-guided PCI was associated with increased HCSF, but not with increased g-CFR. After uncomplicated PCI, one-quarter of patients showed residual CMD. Our approach may help identify patients who may benefit from increased coronary perfusion or show residual CMD.